Cyclins condition the course of a cell cycle through the activation of appropriate
serine-threonine kinases. Any variation in the
cyclins' expression result in pathologies of the cell division, including neoplastic proliferation. Activity of the complexes of
cyclins D1 and E with appropriate
cyclin-dependent kinases may be inhibited by
protein P21 (WAF1/CIP1) which functions as a cell growth cycle inhibitor. As yet, there have been rather few reports on the prognostic value of this
cyclin expression assessment in
gastric cancer, the kind of
neoplasm still characterized by very poor prognosis. The study aimed at the assessment of expression levels of
cyclins D1 and E in surgically removed
gastric cancers, including the analysis of this prognostic value parameter, and attempted to determine some correlations between the expression of the examined
cyclins and selected histoclinical and molecular parameters such as: patients' age and gender, histological type according to the Lauren classification,
cancer stage (TNM), degree of histological
malignancy (G) and level of expression of the cell-cycle regulatory genes
protein products--P53, P21, P27. Immunohistochemical analysis was performed on specimens obtained from radical stomach resections of 80 patients treated in the period 1992-1997 for
gastric cancer stage I-IIIB (TNM-UICC) at the Department of Surgical Oncology, Medical University of Lodz. For immunohistochemical examinations, the LSAB system was used, designed for assessment of
antigen expression. In statistical analysis, Fisher's exact test was applied to evaluate correlations between the analyzed variables and Mantel-Haenschel's test to evaluate their collinearity. For the evaluation of the effect of the analyzed variables on postoperation survival and recurrence-free survival the Cox regression model was used. When analyzing the prognostic value and survival period in association to the
cyclins D1 and E expression levels, a statistically significant correlation was found only in relation to
cyclin E expression: a survival period of minimum 5 year duration was significantly higher in the group displaying a negative, or only faintly positive, reaction to the presence of
cyclin E, than in the group with a strongly positive response. Moreover, the analysis showed statistically significant non-linear dependence between the histological type of
cancer in the Lauren classification as well as a degree of histological
malignancy and the level of
cyclin E expression, and a negative correlation between the level of
cyclin E expression and the stage of
cancer; In addition, a positive correlation between the level of P53 and
cyclin E expression as well as statistically significant non-linear correlation between the level of
cyclin E expression and the level of
protein P21 expression was observed. However, no statistically significant correlations were found between the level of expression of the two
cyclins and the level of
protein P27 expression or between the levels of
cyclin D1 and E expression in
gastric cancer. Out of the two types of evaluated
cyclins only
cyclin E can be considered a significant regulatory factor and a useful prognostic parameter in
gastric cancer.